1. Field of the Invention:
The present invention relates to an improvement of a charging generator which charges a battery for a vehicle.
2. Description of the Prior Arts:
Referring to FIG. 1 as a sectional view, a conventional charging generator for a vehicle will be illustrated.
In FIG. 1, the reference numeral (1) designates a rotor shaft; (2) designates a pulley which is mounted on one end of the rotor shaft together with a fan (3) by a screw (4); (5) designates a rotor mounted on the rotor shaft (1) under pressure and the rotor comprises N, S magnetic poles and coils for magnetizing the magnetic poles; (6) designates a pair of slip-rings mounted on the rotor shaft (1) under presssure and the slip-rings are respectively connected to the coils; (7) designates a bowl-shaped housing which holds the other end of the rotor shaft (1) by a bearing (8); (71) designates a hole for communicating both sides of the housing (7); (8) designates a screw for sealing the hole (71) by screwing into the hole; (9) and (9) respectively a pair of brushes for sliding on the slip-rings (6); (10) designates brush holder for holding the brushes; and the brush (9) and the brush holder (10) respectively have throughholes (9a), (10a) formed in the shaft direction. The reference numeral (11) designates a stator which comprises iron cores placed to face the magnetic poles with each small gap and coils around each of the iron cores; (12) designates a rectifier which is inwardly held on the housing (7) to rectify AC output generated in the coils of the stator (11); and (13) designates bowl-shaped front bracket for holding one of the rotor shaft (1) by the bearing (14) and the bracket has a fitting hole (13a).
Usually, the conventional charging generator has structure for outwardly holding the brushes (9) for assembling ease.
In the apparatus shown in FIG. 1, a pin is inserted into the hole (71) formed on the housing (7) from the outside and the pin is further inserted into the hole (9a), formed on the brush (9) and the hole (10a) formed on the brush holder (10) to hold the brush (9). When the pin is not used, water,fine dust and straw dust are inwardly penetrated through the hole (71) of the housing (7) to adhere to the brush (9) whereby the function of the generator is lost or severe inner rust is formed.
It has been proposed to seal the hole (71) of the housing (7) by a screw (8) as shown in FIG. 1 in order to prevent such trouble. In such structure, the head of the screw is projected in the shaft direction to increase the length in the shaft direction. When the charging generator is equipped in a car, the projected head interrupts the assembly of the other parts. Moreover, the position of the hole for inserting the pin is not easily found. In commercial service, the screw (8) should be taken out for inserting the pin into the hole (71) to cause inferior service.
The apparatus shown in FIG. 2 has been proposed to overcome the disadvantages of the apparatus shown in FIG. 1. In this apparatus, a hardened resin (15) is filled into the hole (71) of the housing (7). In the apparatus shown in FIG. 2, the screw (8) is not used whereby the length in the shaft direction can be shortened in comparison with the apparatus shown in FIG. 1. Moreover, the specific part is not needed to be economical. As shown in FIG. 2, however, the resin (15) may be inwardly penetrated whereby the brush (9) may adhere to the brush holder (10) due to the resin and the function of the brush (9) may be lost. Moreover, it is not easy to remove the resin in the disassembling or testing of the apparatus in commerce. The resealing with the resin may not be carried out in a service shop after reassembling. These disadvantages have been found.